Some tea party organizations have been quietly trading notes with left-leaning advocacy groups as both sides work to derail a series of upcoming free-trade agreements.

Together, they hope to deliver what one opponent of the deals described as a “one-two punch” to proposed trade agreements with Colombia, Panama and South Korea. As liberal groups and labor unions lobby Democrats, tea party members have been calling the Republican freshmen they helped elect.

Some tea party groups have a protectionist slant, opposing pacts that might increase competition faced by U.S. producers, but other groups oppose trade deals because they oppose “big government.” For this faction, free trade should simply be freedom to trade with anyone, instead of a detailed treaty written by governments.

Those concerns differ from labor rights issues and offshoring concerns raised by labor unions and liberals, but Public Citizen’s Lori Wallach said many of the arguments are “different sides of the same issue.”

“I’ve certainly talked to them. We’re not working with them, but I have called them at different times to ask how it’s going,” said Wallach, who is director of the left-leaning group’s Global Trade Watch.

The alliance is less surprising when viewed in light of a Wall Street Journal/NBC News poll from last fall that found a majority of Americans believe free-trade agreements have hurt the U.S. In that poll, 90 percent of Republicans and 84 percent of Democrats agreed that outsourcing is a reason the domestic economy is struggling and people are not being hired.

Coordination between liberal and conservative advocates could be the opposition’s best hope to overcome a strong bloc of support for the trade agreements. Top Republican leaders including Speaker John Boehner (Ohio) and Senate Minority Leader Mitch McConnell (Ky.) have urged the president to deliver these deals, and the White House strongly favors the deals.

The U.S. Chamber of Commerce, National Association of Manufacturers and Heritage Action — the advocacy wing of the conservative Heritage Foundation — are all pushing for passage.

Even FreedomWorks, which works closely with the tea party movement, has argued, “Protectionism only robs Americans of their income and their freedom of choice. The cost of trade tariffs are passed on to consumers in the form of higher prices.”

Some tea party members agree. Ryan Hecker — who helped devise the tea party’s policy platform, dubbed the Contract From America — said he is “100 percent for free trade and for anything that opens up trade barriers.”

Kathryn Serkes, a tea party activist whose Americans for Free &amp; Fair Trade has been reaching out to sympathetic lawmakers and local tea party groups, said she is also for free trade, but that these agreements are anything but.

“It’s like reading the health care bill. You start finding things in there you had no idea were there,” she said, citing strict regulations for men’s pants in the Korean trade deal as an example of regulatory overreach. “A real free-trade agreement would be a very simple agreement between two countries to have free and open trade. I would support that.”

She said several freshman Representatives who signed a March letter endorsing the deals have since changed their minds. She did not name the Members.

“They sort of signed the letter as a general statement supporting free trade,” Serkes said. “President Obama is counting on using the words ‘free trade’ to rope in Republicans on Capitol Hill to support it.”

Tea party groups particularly oppose a provision that lets foreign corporations sue the U.S. government in United Nations and World Trade Organization tribunals. Jim McGovern, a member of Florida’s Martin 9/12 Tea Party Committee, said that is “a threat to the sovereignty of the United States.”

He also questioned why the White House is regulating trade when the Constitution gives that right to Congress, an argument Rep. Ron Paul (R-Texas) has also made against the free-trade deals. The approval process would give lawmakers limited opportunity to debate the agreements and no ability to add amendments.

James Stack, a member of the same tea party group, said, “The middle class is union and nonunion. When a factory closes in a town, whether it’s a union state or a right-to-work state, the jobs are gone. It adds to the deficit and the debt and everything else.”

The AFL-CIO and Service Employees International Union have cited the same reason for opposing the trade deals, but those in favor of them argue that they would actually create jobs.

Alan Tonelson, a senior fellow with the U.S. Business and Industry Council Educational Foundation, said that shared interest between labor unions and tea party groups could help his side win.

“We would hope that the tea parties would make it quite clear to the Republicans they helped elect into office that these trade agreements are a non-starter [as] labor will continue to put as much pressure as it can on the White House and House Democrats,” Tonelson said. At the same time, “That’s the one-two punch that has to work.”

But it is unclear how receptive Republicans will be. Despite tea party ties, Sens. Mike Lee (Utah) and Marco Rubio (Fla.), as well as Rep. Tom Price (Ga.) have endorsed the trade deals.

“These agreements will be a boon to our economy,” Rubio said last month. “Our competitors in China and elsewhere have seized on our missed trade opportunities.”